The GSM/GPRS Modem-RS232 is built with quad band GSM/GPRS engine-SIM900 and works with frequencies 850/900/1800/19.0 MHz’s. The modem is built with RS232 interface which allows it to be connected to a PC as well as a micro controller with RS232 chip (Max 232). The baud rate is configurable from 9600-115200 through AT command. The GSM/GPRS modem has a internal TCP/IP stack to enable you to connect with internet GPRS. It is suitable for SMS voice as well as data transfer application in M2M interface. SIM900 is a quad band modem capable of operating in 850,900,1800,1900 MHz bands and is apt for worldwide compliance.